New Scientist - Manipulative, dishonest and lacking in empathy – the traits that describe a psychopath aren’t particularly pleasant. But the idea that they are also fiendishly clever – as often portrayed in films and TV – isn’t quite true. In fact, in general, psychopaths seem to have below-average intelligence.
You have probably met a psychopath at some point in your life. They make up around 1 per cent of the population, says Brian Boutwell at St Louis University in Missouri. A person is classified as a psychopath if they achieve a certain score on a test of psychopathic traits, which include callousness, impulsiveness, aggression and a sense of grandiosity. “Not all psychopaths will break the law or hurt someone, but the odds of them doing so are higher,” says Boutwell.
Because many psychopaths are charming and manipulative, people have assumed they also have above-average intelligence, says Boutwell. Psychologists term this the “Hannibal Lecter myth”, referring to the fictional serial killer, cannibal and psychiatrist from the book and film The Silence of the Lambs.
But Boutwell wasn’t convinced. “Psychopaths are impulsive, have run-ins with the law and often get themselves hurt,” he says. “That led me to think they’re not overly intelligent.”